Most responses to this argument approach it from the perspective that this is a false dichotomy, that our only choice is Theory A or Theory B.
But in addition to the false dichotomy aspect, this argument also exhibits a gross misunderstanding (or even arrogant ignorance) of how science actually works.
Every new scientific understanding started with a problem. This has been true for the past four hundred years of scientific history.
Consider this snapshot from history:
In 1912, if you asked the following questions, astronomers (and physicists) would have no answer, though they would have lots of speculation.
- Why do atoms emit spectral lines?
- What is the cause of radioactivity?
- Why do atoms bind to form molecules?
- Why does beta decay violate conservation of energy?
- What causes the anomalous perihelion precession of the planet Mercury? Despite numerous searches, no planet has been found to account for this.
- Where are the elements nebulium and coronium in the periodic table?
- What causes the unidentified spectral lines (the Pickering Series) of the star zeta Puppis?
- What energy source powers the Sun and other stars?
- Why are white dwarf stars so small and faint yet can be more massive than the the Sun?
- No one has yet demonstrated that planets orbit due to gravity. No one has been able to do the “Newton's Cannon” experiment.
- The Moon is nearby, yet we do not understand its motion (See "The Problem of the Moon's Motion")
When confronted with these earlier, now solved problems, pseudo-scientists will often try to claim that these earlier problems were not as big (how do you define the 'bigness' of a scientific problem?), or nowhere near as controversial, or not as difficult to solve as the scientific problems of the present. Some go so far as to claim they were never really problems at all.
And yet, many of these problems would take at least a decade and sometimes more, to be solved by the best minds of the day.